<?php 
class log{  
       
    //单例模式  
    private static $instance    = NULL;  
    //文件句柄  
    private static $handle      = NULL;  
    //日志开关  
    private $log_switch     = NULL;  
    //日志相对目录  
    private $log_file_path      = NULL;  
    //日志文件最大长度，超出长度重新建立文件  
    private $log_max_len        = NULL;  
    //日志文件前缀,入 log_0  
    private $log_file_pre       = 'log_';  
   
           
    /** 
     * 构造函数 
     *  
     */  
    protected function __construct(){  
           
        $this->log_file_path     = '../log';  
           
        $this->log_switch     = true;    
       
        $this->log_max_len    = 10000000;  
       
    }  
       
    /** 
     * 单利模式 
     *  
     */  
    public static function get_instance(){  
        if(!self::$instance instanceof self){  
            self::$instance = new self;  
        }  
        return self::$instance;  
    }  
       
    /** 
     *  
     * 日志记录 
     *  
     * @param int $type  0 -> 记录(THING LOG) / 1 -> 错误(ERROR LOG) 
     * @param string $desc 
     * @param string $time 
     *  
     * @since alpha 0.0.1 
     * @date 2014.02.04 
     * @author genialx 
     *  
     */  
    public function log($type,$desc,$time){  
        if($this->log_switch){  
               
            if(self::$handle == NULL){  
                $filename = $this->log_file_pre . $this->get_max_log_file_suf();  
                self::$handle = fopen($this->log_file_path . $filename, 'a');  
            }  
            switch($type){  
                case 0:  
                    fwrite(self::$handle, 'THING LOG:' . ' ' . $desc . ' ' . $time . chr(13));  
                    break;  
                case 1:  
                    fwrite(self::$handle, 'ERROR LOG:' . ' ' . $desc . ' ' . $time . chr(13));  
                    break;  
                default:  
                    fwrite(self::$handle, 'THING LOG:' . ' ' . $desc . ' ' . $time . chr(13));  
                    break;  
            }  
               
        }  
    }  
       
    /** 
     * 获取当前日志的最新文档的后缀 
     *  
     * @since alpha 0.0.1 
     */  
    private function get_max_log_file_suf(){  
        $log_file_suf = null;  
        if(is_dir($this->log_file_path)){  
            if($dh = opendir($this->log_file_path)){  
                while(($file = readdir($dh)) != FALSE){  
                    if($file != '.' && $file != '..'){  
                        if(filetype( $this->log_file_path . $file) == 'file'){  
                            $rs = split('_', $file);  
                            if($log_file_suf < $rs[1]){  
                                $log_file_suf = $rs[1];  
                            }  
                        }  
                    }  
                }  
                   
                if($log_file_suf == NULL){  
                    $log_file_suf = 0;  
                }  
                //截断文件  
                if( file_exists($this->log_file_path . $this->log_file_pre . $log_file_suf) && filesize($this->log_file_path . $this->log_file_pre . $log_file_suf) >= $this->log_max_len){  
                    $log_file_suf = intval($log_file_suf) + 1;  
                }  
                   
                return $log_file_suf;  
            }     
        }  
           
        return 0;  
           
    }  
       
    /** 
     * 关闭文件句柄 
     *  
     * @since alpha 0.0.1 
     * @date 2014.02.04 
     * @author genialx 
     */  
    public function close(){  
        fclose(self::$handle);  
    }  
}  